diff options
Diffstat (limited to 'arch/ppc64/kernel/bpa_nvram.c')
-rw-r--r-- | arch/ppc64/kernel/bpa_nvram.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/bpa_nvram.c b/arch/ppc64/kernel/bpa_nvram.c new file mode 100644 index 00000000000..06a119cfceb --- /dev/null +++ b/arch/ppc64/kernel/bpa_nvram.c @@ -0,0 +1,118 @@ +/* + * NVRAM for CPBW + * + * (C) Copyright IBM Corp. 2005 + * + * Authors : Utz Bacher <utz.bacher@de.ibm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +#include <asm/machdep.h> +#include <asm/nvram.h> +#include <asm/prom.h> + +static void __iomem *bpa_nvram_start; +static long bpa_nvram_len; +static spinlock_t bpa_nvram_lock = SPIN_LOCK_UNLOCKED; + +static ssize_t bpa_nvram_read(char *buf, size_t count, loff_t *index) +{ + unsigned long flags; + + if (*index >= bpa_nvram_len) + return 0; + if (*index + count > bpa_nvram_len) + count = bpa_nvram_len - *index; + + spin_lock_irqsave(&bpa_nvram_lock, flags); + + memcpy_fromio(buf, bpa_nvram_start + *index, count); + + spin_unlock_irqrestore(&bpa_nvram_lock, flags); + + *index += count; + return count; +} + +static ssize_t bpa_nvram_write(char *buf, size_t count, loff_t *index) +{ + unsigned long flags; + + if (*index >= bpa_nvram_len) + return 0; + if (*index + count > bpa_nvram_len) + count = bpa_nvram_len - *index; + + spin_lock_irqsave(&bpa_nvram_lock, flags); + + memcpy_toio(bpa_nvram_start + *index, buf, count); + + spin_unlock_irqrestore(&bpa_nvram_lock, flags); + + *index += count; + return count; +} + +static ssize_t bpa_nvram_get_size(void) +{ + return bpa_nvram_len; +} + +int __init bpa_nvram_init(void) +{ + struct device_node *nvram_node; + unsigned long *buffer; + int proplen; + unsigned long nvram_addr; + int ret; + + ret = -ENODEV; + nvram_node = of_find_node_by_type(NULL, "nvram"); + if (!nvram_node) + goto out; + + ret = -EIO; + buffer = (unsigned long *)get_property(nvram_node, "reg", &proplen); + if (proplen != 2*sizeof(unsigned long)) + goto out; + + ret = -ENODEV; + nvram_addr = buffer[0]; + bpa_nvram_len = buffer[1]; + if ( (!bpa_nvram_len) || (!nvram_addr) ) + goto out; + + bpa_nvram_start = ioremap(nvram_addr, bpa_nvram_len); + if (!bpa_nvram_start) + goto out; + + printk(KERN_INFO "BPA NVRAM, %luk mapped to %p\n", + bpa_nvram_len >> 10, bpa_nvram_start); + + ppc_md.nvram_read = bpa_nvram_read; + ppc_md.nvram_write = bpa_nvram_write; + ppc_md.nvram_size = bpa_nvram_get_size; + +out: + of_node_put(nvram_node); + return ret; +} |